package org.apache.lucene.util;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/**
 * Methods for manipulating strings.
 * 
 * $Id: StringHelper.java 472959 2006-11-09 16:21:50Z yonik $
 */
public abstract class StringHelper {

	/**
	 * Compares two strings, character by character, and returns the first
	 * position where the two strings differ from one another.
	 * 
	 * @param s1
	 *            The first string to compare
	 * @param s2
	 *            The second string to compare
	 * @return The first position where the two strings differ.
	 */
	public static final int stringDifference(String s1, String s2) {
		int len1 = s1.length();
		int len2 = s2.length();
		int len = len1 < len2 ? len1 : len2;
		for (int i = 0; i < len; i++) {
			if (s1.charAt(i) != s2.charAt(i)) {
				return i;
			}
		}
		return len;
	}

	private StringHelper() {
	}
}
